/*
 * Copyright (c) 2017, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.oracle.truffle.regex.tregex.util;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class LaTexExport {

    private static final Pattern specialChars = Pattern.compile("[&%$#_{}~^\\\\]");

    public static String escape(String str) {
        StringBuffer escapedString = new StringBuffer();
        Matcher m = specialChars.matcher(str);
        while (m.find()) {
            String replacement;
            switch (str.charAt(m.start())) {
                case '&':
                    replacement = "\\\\&";
                    break;
                case '%':
                    replacement = "\\\\%";
                    break;
                case '$':
                    replacement = "\\\\\\$";
                    break;
                case '#':
                    replacement = "\\\\#";
                    break;
                case '_':
                    replacement = "\\\\_";
                    break;
                case '{':
                    replacement = "\\\\{";
                    break;
                case '}':
                    replacement = "\\\\}";
                    break;
                case '~':
                    replacement = "\\\\textasciitilde ";
                    break;
                case '^':
                    replacement = "\\\\textasciicircum ";
                    break;
                case '\\':
                    replacement = "\\\\textbackslash ";
                    break;
                default:
                    throw new IllegalStateException();
            }
            m.appendReplacement(escapedString, replacement);
        }
        m.appendTail(escapedString);
        return escapedString.toString();
    }
}
